Scientists Map Bacterial Blueprint That Builds a Natural HDAC Cancer Drug

Overview

• The research team identified the long-missing FR-901375 biosynthetic gene cluster in Pseudomonas chlororaphis subsp. piscium in a Nature Communications paper published on Wednesday, confirming the bacterial source and genetic basis for the drug.
• The authors showed a small β-hairpin docking domain, called βHD, binds a conserved epitope on an ACP-SLiM carrier protein to mediate handoff between polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) modules, explaining how the molecule is assembled.
• The finding was validated by multiple orthogonal methods, including AlphaFold structural models, carbene footprinting mass spectrometry, in vitro reconstitution of enzyme complexes, site-directed mutagenesis, and gene deletions that disrupted production in cells.
• Comparative genomic and evolutionary analyses indicate the ACP‑SLiM/βHD interaction is conserved across related pathways and that gene transfer, duplication, and recombination of variable modules created the natural ‘mix-and-match’ diversity of Romidepsin-related depsipeptides.
• The study provides a tested, evolution-guided blueprint researchers can use to engineer new HDAC inhibitor variants, but translating this into drug candidates will require further biochemical engineering, preclinical testing, and safety studies before any clinical development.